I am not against homeschooling (in fact I'm considering it for my older children), but I do agree with those who have mentioned the social aspect of preschool. I think there are lots of fabulous learning resources available online and in stores, so no matter what you decide you can tap into those. My kids have all gone/are going to preschool, and I think some of the biggest lessons are cooperation, listening skills, taking turns, separating from parents, etc. Our school also does learning and will work with kids on that level as well. For us, we just supplemented the preschool experience with additional learning where the kids were ready and/or interested. If you do preschool at home, just make sure you are including social interaction opportunities as well (not just siblings - that helps, but not quite the same).
I have spoken to several kindergarten and first grade teachers, and the biggest obstacles in their classrooms come from kids at different social/soft skill levels, and not varying academic levels. This is something to consider, especially if you intend not to homeschool all the way through.
That said, if doing it at home be sure to set a pace where your child is being given small challenges and trying new things, but keep it fun and exciting. Don't push too hard or you'll likely turn them off to the learning process. Depending on what y our child already knows, start with things like colors, shapes, body parts, weather words, etc. You can also work on counting and the alphabet, gradually increasing recognition of the letters and numbers and if she's ready the sounds of the letters. As she progresses, you'll get a sense of whether she's ready to read or not. Most kindergartens in our area do not expect children to be reading when they start, but some certainly are. It depends on the child - my oldest didn't care about learning it till she started kindergarten and then picked it up quickly, while my second was reading beginner chapter books before starting. Also, be sure to include lots of songs, especially those with hand motions or other movements in your learning.
Way too long, but best of luck to you whatever you decide to do.